This invention is related to a process and apparatus for making paints that match a standard paint.
Early devices such as those illustrated in Logan et al. U.S. Pat. No. 2,923,438 issued Feb. 2, 1960 provided a method for making paints according to a given formula but did not provide means for color matching the paint to a standard except for visual color matching using estimated additions of colorants to match a standard.
McCarty U.S. Pat. No. 3,601,589, issued Aug. 24, 1971, and McCarty et al. U.S. Pat. No. 3,916,168, issued Oct. 28, 1975, are directed toward computer controlled methods for preparing paints but use the standard procedure of spraying panels with paint, baking the panels and measuring color value of the panels and calculating and reshading the paint to bring the paint within acceptable color tolerance values.
British Pat. No. 1,589,705, published May 20, 1981, describes a general process for making a paint and adjusting the color values of the paint to come within the color tolerance values of a standard paint. However, this method directly utilizes light scattering and optical absorption properties of colorants used in the paints in combination with reflectance values of the paint at several wavelengths to determine the quantity of colorants required to bring the paint within an acceptable standard. When this procedure is used with the equipment disclosed in the patent, it does not provide for accurate color matching of a paint to a standard color and does not lend itself to a totally automated paint matching process.
There is a need for a process and apparatus that automatically, rapidly and accurately dispenses and mixes binder, solvents and colorants for a paint based on a standard formula, measures color values of the paint and shades the paint to within color tolerance values for that paint. The process and apparatus of the invention accomplish the above.